IF EXISTS (SELECT *
           FROM INFORMATION_SCHEMA.ROUTINES
           WHERE ROUTINE_NAME='pSellProducts'
           AND ROUTINE_SCHEMA='dbo'
           AND ROUTINE_TYPE='PROCEDURE'
          )
          DROP PROCEDURE dbo.pSellProducts
GO

CREATE PROC dbo.pSellProducts
AS
/*@@*_____________________________________________________________________

  

_____________________________________________________________________*@@*/

/*______________________ CONSTANT DECLARATIONS _________________________*/

  DECLARE
    @cstrThisProc              NVARCHAR(128),
    @cintErrGeneral            INT

  SET @cstrThisProc            = N'pSellProducts'
  SET @cintErrGeneral          = 50000  -- General error. Used when an
                                        -- error has occurred and no other
                                        -- specific error condition is
                                        -- assigned.

/*______________________ VARIABLE DECLARATIONS _________________________*/

  DECLARE
    @intErrNo       INT,
    @strErrMsg      NVARCHAR(400),
    @intReturn      INT

/*_______________________________ INIT _________________________________*/

  -- Setting NOCOUNT ON prevents additional recordsets with the
  -- "number of records affected" from being returned, which is not
  -- handled the same by all providers, such as for OLEDB vs. ODBC.
  SET NOCOUNT ON

/*________________________ VALIDATE PARAMETERS _________________________*/


/*_______________________________ MAIN _________________________________*/

	SELECT 
		Product.Id,
		[Name],
		ProductTypeId,
		ProducerId,
		Product.SalePrice,
		SellAmount = ISNULL(SUM(BillDetail.Amount), 0)
	FROM Product
	LEFT JOIN BillDetail
		ON Product.Id = BillDetail.ProductId
	
	GROUP BY
		Product.Id,
		[Name],
		ProductTypeId,
		ProducerId,
		Product.SalePrice
	
	ORDER BY [Name]
	
  -- Return value 0 indicates success
  SET @intReturn = 0

lblExit:

  RETURN @intReturn

/*___________________________ ERROR HANDLER ____________________________*/
lblError:
  -- An error has occurred.  On entering this section @intErrNo should
  -- already hold the error number

  -- By default, if there are any open transactions then roll them back
  IF (@@TRANCOUNT > 0) BEGIN
    ROLLBACK TRAN

  END

  -- If return value has not been explicitly set, then use the error
  -- number as return value to signify failure
  IF ((@intReturn IS NULL) OR (@intReturn = 0)) BEGIN
    SET @intReturn = @intErrNo

  END

 GOTO lblExit


